You can use the DSACryptoServiceProvider class to create digital signatures and protect the integrity of your data.

To use a public-key system to digitally sign a message, the sender first applies a hash function to the message to create a message digest. The sender then encrypts the message digest with the sender's private key to create the sender's personal signature. Upon receiving the message and signature, the receiver decrypts the signature using the sender's public key to recover the message digest and hashes the message using the same hash algorithm that the sender used. If the message digest that the receiver computes exactly matches the message digest received from the sender, the receiver can be sure that the message was not altered while in transit. Note that a signature can be verified by anyone, because the sender's public key is common knowledge.

This algorithm supports key lengths from 512 bits to 1024 bits in increments of 64 bits.